Re: [PATCH] tests/intel/xe_vm: Update mmap hammer sections to prefetch next page

["Randhawa, Jagmeet" <jagmeet.randhawa@intel.com>]

On 4/30/2024 3:16 PM, Matthew Brost wrote:
> Adjust mmap hammer sections to prefetch next page by moving BB to within
> PAGE_SIZE /8 of page boundary. This is prefetch next page on all
> platforms, even ones with a smaller prefetch size.
>
> Signed-off-by: Matthew Brost <matthew.brost@intel.com>
> ---
>   tests/intel/xe_vm.c | 7 ++++---
>   1 file changed, 4 insertions(+), 3 deletions(-)
>
> diff --git a/tests/intel/xe_vm.c b/tests/intel/xe_vm.c
> index de2b1a8136..77cf1f7e67 100644
> --- a/tests/intel/xe_vm.c
> +++ b/tests/intel/xe_vm.c
> @@ -1623,10 +1623,11 @@ test_mmap_style_bind(int fd, struct drm_xe_engine_class_instance *eci,
>   		t.fd = fd;
>   		t.vm = vm;
>   #define PAGE_SIZE	4096
> -		t.addr = addr + PAGE_SIZE / 2;
> +#define HAMMER_OFFSET	(PAGE_SIZE - (PAGE_SIZE / 32))
> +		t.addr = addr + HAMMER_OFFSET;
>   		t.eci = eci;
>   		t.exit = &exit;
> -		t.map = map0 + PAGE_SIZE / 2;
> +		t.map = map0 + HAMMER_OFFSET;
>   		t.barrier = &barrier;
>   		pthread_barrier_init(&barrier, NULL, 2);
>   		pthread_create(&t.thread, 0, hammer_thread, &t);
> @@ -1685,7 +1686,7 @@ test_mmap_style_bind(int fd, struct drm_xe_engine_class_instance *eci,
>   		igt_assert_eq(data->data, 0xc0ffee);
>   	}
>   	if (flags & MAP_FLAG_HAMMER_FIRST_PAGE) {
> -		memset(map0, 0, PAGE_SIZE / 2);
> +		memset(map0, 0, HAMMER_OFFSET);
>   		memset(map0 + PAGE_SIZE, 0, bo_size - PAGE_SIZE);
>   	} else {
>   		memset(map0, 0, bo_size);
Reviewed-by: Jagmeet Randhawa <jagmeet.randhawa@intel.com>